Timer for causing brief actuations at prolonged intervals



E. L. SCHELLENS TIMER FOR CAUSING BRIEF ACTUATIONS AT PROLONGED INTERVALS Filed May 7, 1948 Jan. 15, 1952 7 INVENTOR; J E, k-

ATTORNEYS Patented Jan. 15, 1952 TIMER FOR CAUSIN G BRIEF ACTUATION S AT PROLON GED IN TEBVALS Eugene L. Schcllene, Essex, Conn., assignor to The R. W. Cramer Company, Incorporated Centerbrook, Conn., a corporation of Connecticut Application May 7, 1948, Serial No. 25,614

23 Claims.

This invention is a novel timer for causing brief actuations at prolonged intervals; and the illustrated example was devised primarily for operation by an electric motor running at steady speed and arranged for delivering to a driven device, such as an electric switch, a cyclic or periodic repetition of brief actuations or impulses, single or plural, after the lapse of each of a series of long time intervals. In referring to the durations of the actuations and of the intervals it is intended to refer to these factors in a relative sense; taking for example the not infrequent case of an abbreviated actuation, such as a fraction of one hour, to occur once per week at a predetermined clock time on the designated weekday. The reliable actuation of a switch or other device for such a short period after each of a series of such long intervals has presented difllculties in matters of accuracy, reliability, endurance and convenience.

The general object of the present invention is to afford an impulse timer of the character mentioned which will meet the requirements and attain the advantages above recited. As a practical instance of industrial use, for example in a boiler plant, it may prove desirable to provide automatic timing and operation of a boiler blowoff, to be effected on a predetermined day of each week and at a predetermined hour of that day, with a relatively short blow-off period, such as one-tenth of an hour or six minutes of blowoif duration. By using a synchronous motor to drive the timer herein described and causing by the timer the operation of an electric switch, an impulse of electric current is afforded, continuing for example for six minutes, which can readily be connected to a blow-off-opening device comprising for example an electromagnetic means such as a solenoid or a rotary electric motor.

Further objects of the invention include the advantage of compactness and neatness of arrangement of the parts, convenience of adjustment and control, with ready access to the parts, the ability to use certain standard parts such as motors and switches, and the simplicity and cheapness of construction of the characterizing parts giving the desired operation and control as will be more fully described.

To the attainment of such objects and advantages the invention consists in a timer of the kind referred to, giving abbreviated actuations or impulses in cyclical repetition, with long intervals between, which comprises a system of motortumed rotary members or disks preferably in coaxial arrangement for compactness, namely 1) a first rotor which is turned continuously at a constant or steady speed, and (2) a second rotor which has gearing to turn it continuously at a speed slightly different from that of the first rotor, and (3) a third disk or rotatable member, hereinafter called a rotatable actuator, which is adapted to be driven, directly or indirectly, from the first rotor, but only at predetermined times, and having an actuating part or cam operable by it and adapted to produce brief actuations of the terminal device or switch, at the ends of the prolonged intervals; this third disk or actuator being preferably of the nature of a cam operating upon a follower or switch button and having a contour to deliver the desired actuations to the switch device, it being understood that such a cam or actuating disk may be duplicated or fiultiplied so that not merely one, but a number of independent terminal operations are afforded so long as they are all performed within the general interval or cycle of one week, or such other cyclic period as may be characteristic of any particular timer,

constructed according to the present invention. The illustrative means by which the cyclical operation is transmitted from the first rotor to the rotatable actuator consists essentially of a coupling member or lever which is movably mounted upon the first rotor in a manner to be shiftable between a normal first or idle and a second or active position thereby to become -operatively non-engageable or engageable respectively with a complementary or coupling part or shoulder provided on the actuator; while cooperative therewith is a cam or recess or similar means carried by the second rotor and which is adapted by reason of the creeping rotation of the second relative to the first rotor to cause a shift of said coupling member or lever into and then from its active or engaging position; whereby are caused brief rotations of the actuator and actuations of the switch device at or near the close of each prolonged time interval or cycle, due to and predetermined by the gradual creeping or differential rotation of the second relatively to the first rotor. However, instead of the coupling pair, the lever member on the first rotor adapted to thrust the shoulder part carried on the actuator, the shiftable lever could coact with a different transmitting means or train, adapted to deliver intermittent action to the actuator and thence to the actuable device or switch.

In the accompanying drawings, Fig. l is a top aseaaes plan view of a timer embodying'the-present invention and constituting an illustration of the principles thereof, certain portions of the mechanism being broken away for a better showing of other parts therebelow.

Fig. 2 is a front elevation of the timer shown in Fig. 1, with its central parts however shown in longitudinal vertical section.

Fig. 3 is an elevation corresponding to part of Fig. 2 but showing a modified arrangement.

Fig. 4 shows a detail of structure on larger scale than Fig. 1.

Fig. 5 showsa modification of Fig. l in regard to the starwheel mechanism.

Referring to the timer of this invention as illustratively disclosed in the drawing, it preferably comprises a fixed frame part or base l0 shown as an oblong rigid plate upon which all of the other mechanical elements are directly or indirectliy mounted. At the under side of the base plate In is shown a motor ll whose output shaft l4 turns continuously at a constant or steady speed, this specifically and ideally consisting of a synchronous motor ll, preferably of a self-starting induction type; an available such motor being that disclosed in applicant's Patent No. 2,436,231 of February 17, 1948. Said motor, as is conventional, comprises a main casing I2 within which the electromagnetic motor elements are accommodated, providing a synchronous action coordinated with the passage of time. A further conventional element of the synchronous motor is the reduction gear box i3, containing a system of gearing extending from the primary or motor shaft to the final or output shaft M, which latter thereby provides rotary action at a convenient angular speed, such as the slowed rate of one revolution per hour, or any other speed suitable for the operation of a timer mechanism in accordance with-the requirements of the particular use to which the timer is put. The timer mechanism itself, as will be shown, provides an action of intermittency by which its terminal parts 23 to 26 are normally idle but come into active play to deliver an actuation at any desired cyclical interval, such as one actuation per week of 168 hours; during which actuation the terminal element or rotatable actuator may be rotated at a practical speed, such as one single turn per hour of the output shaft or first rotor. adapted to afford eifective actuation of the switch either for the relatively short period of one hour, e. g. at 1 R. P. H., or a more brief fraction thereof, such as 6 minutes or 0.1 R. P. 1-1., or even more brief according to the particuliar control in hand.

Referring further to the output shaft ll of the synchronous motor, an extension part of which constitutes also the primary or driving shaft of the timer, this is shown as extending outwardly from the motor casing 13, or upwardly, through an opening in the base plate l0 and thence through a fixed upright sleeve l5. Said sleeve is mounted upon the base plate and constitutes a bearing both for the shaft ll within and for an exterior rotatable sleeve 28 to be described. Above the sleeve It the shaft I4 is provided with a shouldered collar l'l, between which and the outer sleeve 28 is a retaining ring or washer l8, adapted to provide a modicum of friction and thereby drag for the retarding and holding against undue rotation of the sleeve 26 and connected parts when these are not under driven rotation. The timer receives its power from the motor-turned shaft [4 and for this purpose there is illustratively shown a hub near the top end of the shaft and fast or pinned to rotate therewith and thereby to rotate the first rotor 2| of a system of at least two rotors in the form of rotary disks, at least the first thereof turning continuously at constant or steady speed. A second rotor 50 is shown, also of circular disk form, to be later described, which turns as long as the first does but with an added motion, preferably stepby-step, in short jumps. These two rotors are shown coaxial with each other, and preferably also with one or more rotatable actuators, of discontinuous operation as at the ends of long intervals, as next to be described.

Thedrawings show a plurality of the aforesaid rotatable actuators; thus a first or upper actuator 23 is shown and below it a further or supplemental actuator 24. All of this group if actuators are shown mounted on the same rotary part so as to turn in unison, but they may be independent in operation and effect and each of them may perform some special actuation at a predetermined. time in the general cycle or prolonged interval. The operation of the said cluster of actuators is intermittent or occasional in that they remain idle through the prolonged interval until the cyclical time has come to put them into a brief rotation. For example, the system of actuators may undergo a single rotary operation or make one full turn only once during 168 hours, each actuator preferably making one complete turn during a single hour, that single turn bringing about the desired actuated operations, as of a switch. Each of the rotatable actuators, or the actuating or cam portion of it, is preferably interchangeable so that a timer may be made up with any desired characteristics suitable to the performance to be effected. Such single turn may be considered to accompany the final hourly period or 168th turn of the first rotor in each cycle.

Referring to the mounting of the cluster of rotatable actuators, each of them is shown as of disk form, with a hub 25 mounted fast but removably upon a rotary sleeve 25, previously mentioned, which sleeve surrounds and turns loosely upon a hollow post, as the same upright sleeve it within which the motor shaft 14 rotates. The outer sleeve 26 constitutes a general hub for the several actuators 23, 24 and this sleeve is shown as located above the baseplate I0 and below the washer or friction means Hi.

In order to maintain retarding friction so as to bring and keep the one or more actuators to rest at times when they are not driven, the sleeve or hub 26 may be pressed upwardly from below, as shown in the Fig. 3 modification, along with the rotary actuator disks carried by it, by means of a spring washer 21, shown as an annular cupped spring, which comes under compression when the parts are assembled; the outer edge of the cupped spring bearing downwardly upon the baseplate l0, while the central part of the cupped washer presses strongly upwardly against the lower end of the rotatable sleeve or hub 26. By this arrangement, the system of actuators is in a sense floating upon the cupped spring 21, while being subjected to substantial friction, insufiicient to interfere with the occasional drive of the actuators but sufficient to bring them to rest at their idle or normal position, to await a repeated action at the end of a further prolonged interval. The retarding spring washer 21 is not shown in Fig. 2, but therein the lower end of the rotary sleeve 26 carries a means used for ensuring the I portion or circular are.

3 stopp llir. after each action, of the actuators or cams 23 and 24. as will be later described.

Referring in greater detail to the actuator disks 23 and 24 each of them is shown as having its rim or outer edge formed into a cam as a means of actuating the devices therebeyond.

Thus, referring first to the upper actuator disk I 23, its cam edge is shown as formed with four successive peripheral portions, acting on the righthand switch 43. The first of these cam parts is the outer portion 23, shown as a concentric These parts turning counterclockwise as seen in the top view of Fig. 1, the next cam portion in order is the cam drop 33, and this should be substantially radial or even undercut, as shown, so as to ensure an abrupt or instantaneous action upon the follower 41 to be described. Beyond the cam drop 33 is a concentric inner dwell 3I, followed by a cam rise 32, extending for a suitable peripheral distance, and rising to the full radius of the outer concentric portion 23. The action of the cam rise 32 gives a relatively slow outward thrust upon the actuated follower. In this instance of the great variety of cam disks that may be employed, the outer dwell 23 occupies almost the entire periphery of the disk 23, the inner dwell 3| occupying only a 'small angle, and the cam rise 32 a yet smaller angular extent of periphery. The operation of the cam 23 thus constructed will be more fully described.

Another instance of an actuating cam is that carried by the underneath disk 24; and the purpose of operation thereof may be wholly independent of the upper disk, excepting that both, and any other or further disks, are rotated at the same times and speeds and through the same cyclic periods. The actuator disk 24 has at its periphery a concentric outer cam portion 33, indicated in Fig. 1, followed by an abrupt drop 34, shown in dotted lines, with a final cam rise 36 to the outer periphery, the drop and the rise being separated by a concentric inner dwell 35. In this instance, the disk is designed so that, between the sudden cam drop 34 and its slow rise 36 the two concentric cam portions each occupy about half of the circumference; this arrangement being reflected in the specific actuation of the switch 4| or other device beyond.

It should be understood that the active cam surfaces thus described, which come into play by the rotation of the actuator disk 23 or 24, while shown applied directly at the periphery of such disk, may be otherwise applied with equivalent results. Thus, while in Fi s. 1 and 2, the cam edge of the disk 23, for example, directly actuates the terminal switch or other device, the actuation from the disk 23 may be indirect, for example, with further gearing such as that shown in the modification of Fig. 3. In said Fig. 3 the actuator disk 23 is gear-toothed at 16 and thus adapted to drive a pinion 11, shown as mounted upon a rotatable cam 23', in any desired arrangement, turnin for example, upon a bearing stud I3 which is nonaxial to the shaft I4, preferably parallel thereto. The periphery of the intermittently rotatable remote cam 23 may be similar to the peripheries of either disk 23 or disk 24, or with any other conformation according to the particular operations desired.

Referring further to the intermittent rotation of the actuator disks such as 23, 23 and 24, their rotation is preferably effected directly from a stud or pin I3 which, with its mountings, will be further described, the same adapted to thrust directly, in a rotary manner as the first or driving rotor 2| turns, against an upstanding contact shoulder or lug 33 on the topmost disk 23 of the actuator disks. The stud I3 is mounted movably on the driving rotor 2| so as to shift into and from operative position, thus to afford engagement or non-engagement with the shoulder 33. While, however, this couple of elements I3, 33 is a convenient and preferred mode of intermittent drive to the actuator disks, other modes of drive could be used. For example, the drive from the rotor to the actuator may be by means of a speeddecreasing device, as a star wheel, upon which the stud I3 acts only when in its engaging position, with connections from the star wheel to the actuator, thus aflording an extremely prolonged cycle such as a month or even a year. The illustrated arrangement, however, is desirably simple and will be further fully described.

When the depending stud 13 is in its active position to thrust against the upstanding lug 33,

the rotation of the first or driving rotor 2| is communicated to the system of actuator disks, by the counterclockwise thrusting action of the stud upon the lug, after they have made contact. The cam periphery of the rotatable actuator 23, or that of the corresponding actuator 23 in Fig. 3, causes direct actuation of the switch device 43 at the righthand side of Figs. 1 and 2, shown as a so-called snap-switch operated by a resilient action between the open-circuit and the closed-circuit positions of the switch. Similarly at the lefthand side the cam of the second disk 24 operates directly upon the snap-switch 4|.

The lever 68 with its stud and the shoulder 33 may be considered as couplers, 63 being a coupling member and 33 a coupling part; these being adapted to be coupled to each other or uncoupled to effect or terminate actuation. In referring to the idle and active positions of the coupling, driving or transmitting member or lever 63, 13 on the first rotor 2|; the idle position is that of its non-engageability with the actuator disk 23 or with the coupling part 33 of the latter; the active position of said member being that of engageability of the member with the actuator 23 or coupling part 33, as shown in full lines in Fig. l; or, stated differently, the idle position is the dotted-line non-transmitting or non-thrusting position of the transmitting or coupling member or lever, whereas its active position is its full-line engaging, transmitting or thrusting position wherein it can engage and thrust the actuator, or the coupling part thereof, to cause the rotation of the actuator from the first rotor.

The illustrated snap-switches 40 and 4| are examples of various devices by which impulses or electric currents may be delivered under timed control for various purposes. Each of the shown switches may be of the kind wherein its interior circuit is normally closed by the snap action of its spring (or normally open if preferred) and reversible when the lever arm or button of the switch is thrown or depressed; and a suitable type of switch for present purposes being a marketed snap switch designated the W-type switch, with single pole, double throw. Patents showing this type of switch are No. 1,960,020 of 1934, McGall, and No. 2,230,191 of 1941, Knight.

Referring particularly to the lefthand switch 4i this is shown as having exposed circuit back terminals 42 and 43 through which the interior circuit is closed, as stated. At the front is a mechanical contact button 44, and bearing against it a yielding contact arm or lever 45, tending to swing cut, away from the switch and toward the timing mechanism. This operating arm 45 may be springy, but preferably is pivoted at 45 at one end, its free end being formed as an outward bent portion 41. The arm 45 tends to swing outwardly to its dotted position shown in Fig. 1 by the outward pressure of the button 44, which may be supplemented by a coil spring 48. The switch is shown mounted closely adjacent to the actuator disk 24 of the timing mechanism, so that the follower or bent end 41 rides upon the disk periphery acting as a cam. The outer concentric periphery portion 33 of the disk is shown holding the arm away from the disk but depressed into the switch, so that the circuit, normally closed, is thus held open; which condition continues until the rotation of the disk brings the follower beyond the cam drop 34, whereupon the arm swings toward the disk and the follower 41 rides along the inner dwell 35 of the disk, the arm taking the position shown in dotted lines, by which the button 44 snaps outwardly to its normal position, thus closing the interior circuit to deliver an impulse of current, continuing until later at the cam rise'38, the switch parts are restored and the-circuit broken.

For controlling the intermittent operation of the actuator from the first rotor 2| there is provided the second rotor 50, coaxial with 2|, and turned constantly at a slightly diiferent or slower average speed than 2|, thus to afford a greatly reduced differential or relative speed, herein availed of for the control of the intermittent short drive periods between the long intervals. Like rotor 2|, rotor 50 is preferably disk-like, and as a part of it there is a somewhat smaller upper disk or round plate These unitary circular plates 50, 5| have a common hub 52 turning loosely on the central shaft l4 and resting on the collar l1. The upper plate 5| has a peripheral cam recess, shown as a V-notch 53, to receive after each complete relative rotation a follower or finger 1| provided on one arm of the shiftable lever 58. See Figs. 1 and 4.

For the motor drive of the second rotor 5!! at a differential speed it may have any suitable gear train from the motor shaft M; a convenient plan being to derive the second rotor rotation through and from the motor-turned first rotor, for example as follows. The lower plate or rotor body 50 has its peripheral edge 54 finely toothed, forming a gear for the turning of the second rotor. The first rotor, slightly larger than the second, carries fixedly at its rim an enlargement, boss or block 56 that is vertically bored to form a bearing in which turns an upright shaft 51, the lower end of which protrudes and carries a pinion 58 which meshes with the gear 54 consisting of the toothed edge of the rotor plate 50. Without more, and due to the bearing friction, the two rotors would turn always in unison; but the following means afford the slight and slow creeping operation of the second relative to the first rotor. The pinion shaft 51, above the bearing 56, carries a collar 60, on which rests the hub SI of a star-wheel 62, consisting of seven spokes, in this case, projecting radially from the hub 6|, with spaces 63 between spokes. Cooperating with the star-wheel is an upstanding fixed pin or feed finger 54 in the path of the spokes and adapted to enter the spaces 53 of the wheel so that with each full turn of rotor 2| the star-wheel makes one-seventh of a turn. The pin projects upwardly from a supporting bracket 55 mounted by screws 55 atop some fixed part such as the switch 40. Depending on rotational directions and arrangements each starwheel action could give the second rotor either an increment or decrement of relative rotation. the former being shown. The operating P may be variously arranged.

Thus the second rotor 50, as shown, is given a slight increment of rotation, relative to the driving rotor 2| in each full rotation of the latter, causing a gradual but preferably jumping or discontinuous creeping of the cam notch or recess 53 around its path, to overtake at regular long intervals the follower finger 1| and thus cause the lever 55 to swing into active position for its stud 10 to become operative to advance the rotary actuator or disk 25. The gear ratio between the star-actuated intermittenly advanced pinion 58 and the gear 54, which is the rim of the second rotor, determines the difference in rotary speeds of the two rotors and thereby the intervals between successive shiftings of the lever 68 to bring about the short or single-turn rotation of the rotary actuator at long intervals. For example, with the first rotor 2| making one turn per hour, the second rotor, by a simple proportioning of the gearing elements 54 and 52 and 51 and 58 tothe toothed rim 54 of the second rotor, can be made to produce one complete differential turn of the second rotor in each I58 turns of the first rotor; whereby at weekly intervals of 168 hours the lever 68 is caused to operate to bring about the brief rotation of the rotary actuator 23. As shown, the star-wheel device gives a ratio of 7 to 1 and the gearing 58, 54 a ratio of 24 to 1, the combination yielding the ratio of 168 to 1 for the slow or stop by step gain of the second relative to the first rotor.

Referring further to the lever 55, shown pivoted at 59 on the first rotor 2|, this is in the nature of a coupling member. bringing about the coupling of the first rotor, at suitable times, to the rotary actuator, specifically the coupling lever by its depending stud 1|! serving, at the end of each interval, to thrust advancingly the actuator. The shifting lever is preferably swingable, being shown fulcrumed at 69 on the first rotor, its long arm carrying the depending stud 10 and its short arm carrying the pointed finger 1| which, at the predetermined intervals, e. g. at the end of a week, or just short thereof, drops into and issues from the cam notch or recess 53 of plate 5| of, the second rotor 50. The lever movements are aided by the presence of a spring 12, shown as a spring strip, attached to the first rotor and bearing upon the lever in a way to swing the finger 1| inwardly against the rim of the upper disk or plate 5| of the second rotor, so that at the end of each relative turn of the second rotor the finger drops into the recess, by the spring action, thus shifting the lever stud 1U fairly quickly from its idle position to its active'position as shown by the dotted and full lines in Fig. 1. This jump action occurs at the start of the final or 168th hourly period.

The action just disclosed is relatively rapid, the follower 1| dropping quickly into the recess 53, due to the fact that the star wheel is passive throughout substantially the full rotation, during one hour, of the first rotor, and then makes abruptly its one-spoke shift, becoming again passive for another full turn or hour. The star wheel, thus operating the train 58, 54 only during a very short extent of each hourly rotation, causes relative steps or advancing Jumps of the rotor 58; one such jump, near the final turn of each interval, as just described, allowing the finger II to drop completely into the recess 53; and the next or final step one hour later causing the finger to rise again, being cammed out of the recess to the general periphery of the disk 5| of the second rotor. Between these two jumps, fully into and then out of the recess, separated by one hour. the lever 68 and its stud I8 first take their active or engageable position, Fig. 1, so that the stud may thrust the shoulder 38 and the actuators, and at the end of the hour shift again to take their inoperative position, the dotted lines in Fig. 1, leaving the actuators undriven until the end of another long or 168 hour interval: the two actuators thus making their required complete single rotation at the end of each interval, their cam contours delivering the desired brief actuations to the switches 40 and 4|, for example for a fraction of one hour during each interval of one week.

The relation between the finger or follower ll of the lever 88 carried on the first rotor and the recess 53 on the relatively advancing second rotor 50 must be accurately predetermined. When the finger enters the recess, this should be a relatively abrupt action, caused by a single star wheel advance, and causing the lever 68 and stud HI to shift from idle to active position, as seen on Fig. 1. This initiates the advance of the shoulder 38 and actuator 23. At the cyclic end of the final rotary advance of the two rotors and the actuators, the new star wheel advance operates, through the cam notch or recess 53, and this should be'arrangcd as shown to give a relatively abrupt rise of the finger II, which rides out of the recess, so that the stud I is at this time cleared from the path of the shoulder or target 38, against which it has been thrusting for a single turn. One spoke advance of the star wheel causes, in the second rotor 50 and recess 53, an angular travel of 360 divided by 168 or about 2.141", which, considering the in clined side of the recess 53, should be enough, or more than enough, to let the finger 1| drop fully into the recess, by the abrupt action of the star wheel, at the end of the penultimate rotation of the first and second rotors and rise fully out of the recess, relatively abruptly. at the end of their final rotation. In other words, the finger must drop fully into the recess in one star-wheel-induced control action of the second with relation to the first rotor, and on the next action ride out of the recess, at the end of the final rotor rotation of the cycle; so that the stud 10 thrusts the shoulder 38 and the connected actuators for exactly one revolution, during the lapse of one hour, leaving the shoulder in its normal, initial or final position ready to cooperate again later on at the end of the next succeeding week or cycle. The preferred relation of recess 53 and finger is shown in Fig. 4.

By the timing means and actions thus specifically disclosed, the general objects and operations referred to in the preamble of this specification are afforded. In considering the described actions it should be remembered, of course, that the first and second rotor do not cease their ordained rotation but continue on from the end of each cycle into the next. It should also be "explained that the star wheel is shown for convenience in Fig. I at the midpoint of a single relatively quick advance, whereas it should appear at the end of such an advance in order to correspond with the illustrated positions of the affected parts 5|, 53, ll, 88 and I0.

An additional device which is a. desirable supplement to the described mechanism, and which may be considered a yieldable positioning device for the cooperating stud or thruster 10 and the shoulder 88, is shown on Figs. 1 and 2 and may be described as follows. It consists of a fixedposition dog or detent 8| which is spring-pressed toward a rotatable part turning with the actuators 23 and 24, and a cooperating notch or indentation 82 of said rotatable part, which may be the actuator hub 25, and is so shown, although an added notched part of greater diameter would possess operational advantages. The head or roller of the dog 8| may drop into the notch 82 when the actuator 23, and the shoulder 88 thereof, are in their normal, that is, initial or final, position i. e., at the finish position, or what is the same thing, the restart position, of the shouldered actuator, whereat the dog and notch are in yieldable holding engagement. The dog member does not rotate or travel but is shown mounted upon a fixed post or block 84 attached upon the base plate H) of the timer. For a particular reason to be explained the dog notch 82, on the rotatable part or hub 25 is formed with slanting or cam-like sides. By this arrangement the inslanting first or entrance side of the notch has a strong tendency to cause the spring-pressed dog, when it has once entered the notch, to pass relatively inwardly with a quick or snap movement; thereupon coming to rest at the bottom of the notch, as shown, with the hub 25 and the actuators in their normal position in which they remain at rest throughout the long interval of the timer until the final brief period of timer actuation during which the actuators are to perform a single complete rotation, coming again to rest with the dog in the notch. Stated otherwise, as the thrust-stud l0 forces the actuators to travel or rotate with the driving rotor 2| during the final lap of the total cycle, the dog approaches relatively the notch near the end of the actuator rotation and enters the notch, causing a snap advance of the shoulder 38 and the actuator to their shown normal or rest position, this snap action or slight advance drawing the actuators slightly away from the thrust-stud 10, thus clearing the stud and facilitating the shift of the stud from its active thrust position to its idle position. When, at the end of the next prolonged interval, the actuators have to be brought into rotation again for one turn, the stud 10, by that time restored to active position, is readily able to effect thrust and advance of the actuators for the reason that the dog 8|, remaining spring-held in the notch 82, as shown, is readily able to be cammed out of the notch by the second or exit incline of the notch; the dog thereafter standing ready at the periphery of the hub 25 to repeat its cooperation with the notch as already described.

These actions of the positioning device consisting of the dog 8| and the notch 82 are structurally related to the actions of the lever 88 and its finger 1| engageable in the recess 53 of the second rotor. Thus, about the time that the finger II is to pass out of the recess 58, to cause the stud 18 to shift into idle position, the dog is intended to reach its notch and start its quick descent into the notch, producing the snap action which thrusts the shoulder 38 and actuator slightly ahead of the stud 18, as shown. This kicking away of the shoulder occurs just previously to the inward swing of the lever 88 and stud 10 which, at the time of this shift, are therefore clear of the shoulder. This inward shift of the stud to idle position is a quick movement, as already explained, so that the stud will have reached its inward idle position before the continued advance of the rotors brings the stud ahead to the position of the shoulder; wherefor the stud is readily able to pass safely by the shoulder. leaving the actuators at rest. and this condition obtaining throughout the succeeding cycle or interval of the timer until, near the end thereof, the actions are completed and then repeated.

The described supplemental positioning device 8|, 82, promotes reliability in the action of the timer, more especially as to the cooperation between the stud 10 and shoulder 38 through which the actuators derive their occasional rotary motions from the first rotor through the control of the second rotor. To review the results of the device 8l, 82, it affords a clearance between stud l and shoulder 38 so that, before the stud reaches the shoulder to effect a rotation it is able safely to shift from idle into active position, ensuring that it will come behind the shoulder and properly deliver its thrust. The device also avoids failure of action by friction or drag between the stud and the shoulder when the former is shifting to or from its active position, this being due to the gap or clearance which at both of these occasions is brought about by the snap action produced by the dog 8! snapping into its recess. Additionally, the device provides the useful function of holding the rotary actuators safelv in their normal or initial position throughout the long interval, until the final rotation: the dog yieldingly locking the notched hub 25 and the actuators and preventing unintended creeping or other displacement thereof throughout the long interval until the final rotation in which the actuators partake.

Many mechanical variations of structure and action may be employed within the principles of the invention, the following being recited as examples. The indirect cam action between actuator 23* and switch 4| was explained in connection with Fig. 3.

The cam recess 53 in the second rotor upper plate 5|, and the finger II, engaging the recess. may be reshaped to afford an abrupt locking or positive angle of engagement at one side of the recess while allowing the finger to ride out of the recess smoothly at the other side, for example as shown in Fig. 4.

Referring to the starwheel actuating pin 84 on bracket 65, the pin bein shown radially outward of the starwheel axis, this arrangement mav be reversed by extending the bracket above the starwheel to where the pin can depend into starwheel engagement at a point radially inward, thus communicating rotation to the starwheel and to the rotor upper plate 5| in directions opposite to those shown. e. g. when using a motor whose output shaft l4 turns clockwise.

To ensure the starwheel always stopping, after after each jump actuation, in a uniform position of rest, its hub 60 or a special disk 90 on the shaft 51 may be formed with flattened sides,

seven for a seven-spoke starwheel, cooperating with a bar or spring 9| arranged to press resiliently against a flattened side, thereby yieldingly positioning and holding the starwheel and affording greater accuracy of action. When this position- I ing device is used, the position of engagement and holding of the dog 8| with the notch 82 should correspond with a position of engagement and holding of the starwheel as described. This is shown in Fig. 5.

What is claimed is:

l. A timer for causing at prolonged cyclic intervals brief periods of actuation of an actuable device, comprising in combination, rotors including a first rotor geared from a motive source to rotate continuously at a predetermined speed, the same having a coupling member movably mounted thereon, and a second rotor coaxial with the first, said rotors being combined with gear means whereby thesecond rotor is rotated continuously at a predetermined speed slightly different from that of the first rotor, providing thereby a greatly reduced differential speed between the rotors; and a rotatable actuator coaxial with said rotors and having a coupling part which by engagement with said coupling member is adapted to be driven from the first rotor at predetermined times, and an actuating part operable from said actuator and adapted thereby to produce brief operations of the actuable device; the said coupling member being mounted on said first rotor in a way to be shiftable between idle and active positions wherein it is non-engageable and engageable respectively with the said coupling part of the actuator, and a control means on the second rotor adapted by reason of the differential rotation of the second relative to the first rotor to cause at predetermined points of time in each cyclic interval a shift of said coupling member first into and briefly thereafter out of its active engageable position; whereby there is caused a predetermined brief rotation of the actuator and an actuation of such device in each prolonged time interval.

2. A timer for causing at prolonged cyclic intervals brief periods of actuation of an actuable device, comprising in combination, motor-turned rotors including a first rotor geared to rotate continuously at a predetermined constant speed, and a second rotor coaxial with the first, said rotors being associated with differential gear means wherebythe second rotor is rotated continuously at a predetermined speed slightly diilerent from that of the first rotor, providing thereby a relatively slow rotary creep between said rotors; and a rotatable actuator coaxial with said rotors and having a coupling part through which said actuator is adapted to be driven from the first rotor at predetermined times; together with a coupling member mounted on said first rotor to be shiftable between idle and active positions wherein it is operatively non-engageable and engageable respectively with the said coupling part of the actuator, and a control means operable by the second rotor by reason of its progressive creeping rotation relative to the first rotor to cause at predetermined points of time in each cyclic interval a shift of said coupling member first into and shortly thereafter out of its active engageable position; whereby there is caused a predetermined brief rotation of the actuator in each prolonged time interval or cycle.

3. A timer for causing brief actuations at prolonged cyclic intervals, comprising coaxial motorturned rotors, including a first rotor geared to rotate continuously at a predetermined speed, and a second rotor having gear means whereby it is rotated at a mean or average speed slightly different from that of the first rotor, providing thereby a greatly reduced differential speed; an actuator adapted to be rotated from the first rotor during a predetermined brief period in each interval; a transmitting member mounted on the first rotor to be shiftable between nontransmitting idle and transmitting active positions, and mechanical connecting means operable from said transmitting member when in its active position and extending to said actuator to engage and rotate the latter; and a control means operable by the second rotor adapted by reason of the differential rotation of the second relative to the first rotor to cause at a predetermined point of time in each cyclic interval a shift of said transmitting member into its active position and at a briefly later point of time a return to its idle position; whereby there is caused a brief rotary movement of the actuator throughout a predetermined brief period in each prolonged time interval or cycle.

4. A timer for causing brief actuations at prolonged cyclic intervals of an actuable device, comprising motor-turned rotors, including a first rotor geared to rotate continuously at a predetermined constant speed, and a second rotor coaxial with the first, said rotors being associated,

with gear means whereby the second rotor is rotated at a mean or average speed slightly diiTerent from the speed of the first rotor, providing thereby a greatly reduced differential speed as between the rotors; a rotary actuator adapted to be driven from the first rotor during a predetermined brief period in each interval and having an actuating part to produce brief operations of the actuable device; together with a transmitting member mounted on said first rotor to be shiftable between non-transmitting idle and transmitting active positions, and mechanical connecting means operable from said transmitting member when in its active position and extending to said I actuator to enga e and rotate the latter; and a control means on the second rotor adapted by reason of the differential rotation speed of the second relative to the first rotor to cause at a predetermined point of time in each cyclic interval a shift of said transmitting member into its active position and at a briefly later point of time a return to its idle position; whereby there is caused a, brief rotary movement of the actuator and actuation of such device throughout a predetermined brief period in each prolonged time interval or cycle, such period commencing with the actuator in its normal initial angular position of rest and continuing for a full rotation and ending with the actuator again in its normal position.

5. A cylindrical timer of the kind set forth, having synchronous-motor-turned coaxial first and second rotors geared for slightly different speeds whereby a prolonged interval elapses between repetitions of a given set of conditions, with a single active and many idle rotations of said rotors occurring during each interval; an actuator coaxial with said rotors and adapted to be turned from the first rotor for a single rotation in a brief final period at the end of each interval and then to rest until the final period of the next interval; a drive-transmitting member shiftably carried on the first rotor and having mechanical connections to the actuator to drive the latter, said member being shiftable between a driving active position and a non-driving idle position for causing and stopping respectively the transmission of drive to the actuator; and a control means carried on the second rotor and operable cyclically to shift said transmitting member on the first rotor into its idle position and active position respectively at the start and finish of the final period of each cylindrical interval.

6. A timer as in claim 2 and wherein the rotatable actuator is disk-like and carries not only 14 the coupling part or shoulder by which it is thrust rotatingly, but also the actuating part or cam by which the actuator produces operations of the device or switch.

7. A timer as in claim 3 and wherein the rotattable actuator is disk-like and carries not only the coupling part or shoulder by which it is thrust rotatingly, but also the actuating part or cam by which the actuator produces operations of the device or switch.

8. A timer as in claim 2 and wherein the rotatable actuator is disk-like and carries the coupling part or shoulder by which it is thrust rotatingly, and carries also a gear, said gear in mesh with a second gear on a countershaft, and said countershaft carrying a part or cam to operate the device or switch.

9. A timer as in claim 2 and wherein the gear means by which the second rotor is rotated continuously at a predetermined mean speed slightly diiferent from the speed of the first rotor comprises, mounted eccentrically on the first rotor, a rotatable star wheel on the shaft of which is also a pinion in mesh with a gear on or rotating with the second rotor; with a non-rotating or fixed pin positioned to cooperate with and turn the star wheel, spoke by spoke, as the rotors rotate approximately in unison; thereby to cause differential gain or loss of rotary speed as between the rotors for the purposes set forth.

10. A timer as in claim 3 and wherein the gear means by which the second rotor is rotated continuously at a predetermined mean speed slightly different from the speed of the first rotor comprises, mounted eccentrically on the first rotor, a rotatable star wheel on the shaft of which is also a pinion in mesh with a gear on or rotating with the second rotor; with a non-rotating or fixed pin positioned to cooperate with and turn the star wheel, spoke by spoke, as the rotors rotate approximately in unison; thereby to cause differential gain or loss of rotary speed as between the rotors for the purposes set forth.

11. A timer as in claim 2 and wherein the control means operable by the second rotor by reason of its progressive differential rotation relative to the first rotor comprises a cam recess at the periphery of the second rotor with contour having entrance and exit inclines to and from the base. of the recess, and a cooperating finger swingably mounted on the first rotor with its end tapered and spring-pressed to enter and leave said recess, said finger being part of or operatively connected with the coupling member or lever carried on said first rotor; whereby the slow relative rotation of the second rotor brings said recess progressively around for engagement with said finger, thereby causing the finger in one rotation to enter and in the next rotation to leave the recess, thereby correspondingly swinging the coupling member first to its active and then to its idle position, in successive rotations, so that, near the end of each cycle, by the aforesaid control by said second rotor, the said coupling member causes the actuator to make one rotation while the couplin member is in its active position, ceasing suc rotation when the coupling member is returned 'to idle position by the action of the recess upon the finger.

12. A timer for causing at prolonged cyclic intervals brief periods of actuation of an actuable device, comprising in combination, motor-turned rotors, including a first rotor geared to rotate continuously at a predetermined speed, and a second rotor coaxial with the first, with diflerential tively slow creep gear means operatively connected to both rotors whereby the second rotor is rotated continuously at a predetermined speed slightly different from that of the first rotor, providing thereby a relaas between said rotors, with one overtaking the other near the end of each interval; and a rotatable actuator coaxial with said rotors and having a coupling part through which said actuator is adapted to be driven from the first rotor; together with a coupling member mounted on the first rotor to be shiftable between engageable active and non-engageable idle positions respectively into and out of the path of said coupling part for thrusting and non-thrusting cooperation with said coupling part, and a control means operable by the second rotor by reason of its progressive creeping rotation relative to the first rotor to bring about at the beginning of the final brief period of each cyclic interval the shift of said coupling memben into its active position thereby to cause the drive of the actuator for a single rotation, and thereupon to bring about the shift of said coupling member back into its idle position to cease such drive; together with a positioning device associated with a rotary portion of the actuator for yieldingly holding the actuator in its initial position of rest, throughout each cycle except during its each brief period of rotation when driven from the first rotor.

13. A timer as in claim 12, having a frame and the rotary actuator having a hub portion, and wherein said positioning device comprises a notch on the actuator hub and a dog on the frame spring-pressed to enter the notch; said parts being so relatively located that when said coupling member is in idle position, the dog holds the actuator in its initial position of rest.

14. A timer as in claim 13 and wherein the notch has sloping sides providing cam action on the dog whereby when the notch by the rotation of the actuator during the final period reaches the dog, the dog snaps into the notch, thereby camming the actuator ahead with a snap motion and causing the coupling part to clear the coupling member and avoid drag upon the coupling member as the latter shifts to idle position.

15. A timer as in claim 14 and wherein the second rotor derives its differential rotation from the first rotor through a train including a star wheel carried by the first rotor cooperating with a fixed pin whereby the speed diflerential between the two rotors consists of a relative jump motion or increment, whereby at the start and end of the final rotation in each cycle the recess and finger operation of shifting the coupling member occurs with jump action,aifording quick shift of said member into and from its idle position.

16. A timer as in claim 12 and wherein the second rotor derives its differential rotation from the first rotor through a train including a star wheel carried by the iirstrotor cooperating with a fixed pin whereby the speed differential between the two rotors consists of a relative jump motion or increment, whereby at the start and end of the final rotation in each cycle the recess and finger operation of shifting the coupling member occurs with jump action, affording quick shift of said member into and from its idle position.

1'1. The timer as in claim 12 and wherein as the cyclic interval reaches the start of its final period of one rotation wherein the actuator is turned advancingly with the first rotor the elements, by reason of their coaction and relative positioning, undergo the following operations: the second rotor by said recess and finger cause the coupling member to shift into active position thereby to overtake and contact the coupling part held with clearance by said dog and notch, thus starting the single rotation of the actuator, the dog riding out of the notch; after said single rotation the dog snaps into the notch and snaps the actuator ahead to clear the coupling part from the coupling member; the control recess elects the finger and shifts the coupling member to idle position; the actuator thereby stopping in its normal initial position of rest.

18. A timer for causing at relatively prolonged predetermined cyclic intervals relatively brief predetermined actuations of an actuable device as a switch, comprising a power-operated continuously-turning driving rotor; an intermittently rotatable actuator adapted by each rotary advance thereof to actuate such actuable device; an engageable and disengageable coupling means operable between said driving rotor and said actuator and adapted by its engagement to bring about each such rotary advance of said actuator; and a control means operating cyclically in coordination with said driving rotor adapted to bring about at the ending of each of a series of such prolonged intervals of driving rotor rotation the engagement and early following disengagement of said coupling means; thereby to cause cyclically repeated actuations of said actuable device for such brief periods at such prolonged cyclic intervals.

19. A timer as in claim 18 and wherein the driving rotor has a constant predetermined speed; and the control means comprises a controlling second rotor provided with a differential gear means between the driving and controlling rotors and giving to the controlling rotor a speed slightly different from that of the driving rotor and in the same direction; and a cam means between the controlling rotor and the coupling means operable to cause the coupling means to become engaged and disengaged thereby to rotate briefly and thereupon to cease rotation of the actuator.

20. A timer as in claim 19 and wherein the driving rotor, the controlling rotor and the actuator are disk-like elements mutually coaxially arranged; the actuable switch being eccentrically offset from the common axis of such elements.

21. The timer as in claim 19 and wherein the coupling means consists of a coupling member as a lever movably mounted on the driving rotor to shift between engageable and non-engag'eable positions and a coupling part as a shoulder on the actuator.

22. The timer as in claim 18 and wherein the coupling means consists of a coupling member as a lever movably mounted on the driving rotor to shift between engageable and non-engageable positions and a coupling part as a shoulder on the actuator.

23. A timer for causing at greatly prolonged predetermined cyclic intervals relatively brief predetermined actuations of an actuable device,

- comprising a power-operated continuously advancing driver; an intermittently advancable actuator adapted by each advance thereof to actuate such actuable device; an engageable and disengageable coupling means operable between said driver and said actuator and adapted by its engagement and disengagement to bring about each such intermittent advance of said actuator;

and a control means operating cyclically in coordination with said driving rotor adapted to bring about at the ending 01 each of a series of such prolonged intervals 01' driver advance the engagement and early following disengagement 0! said coupling means; thereby to cause cyclically repeated actuations of said actuable device for such brief periods at such prolonged cyclic intervals.

( EUGENE L. SCHELLENS.

REFERENCES CITED The following references are of record in the file 01 this patent:

18 UNITED STATES PATENTS Number Name Date 1,863,658 James June 21, 1932 2,164,037 Lockett June 27, 1939 2,341,774 Harris Feb. 15, 1944 2,471,873 Hunt May 31, 1949 FOREIGN PATENTS m Number Country Date 196,116 Germany Feb. 27, 1908 OTHER REFERENCES Hiscox: Mechanical Movements, Devices and 

